Three people were stabbed Saturday night when a fight broke out at a crowded Bronx roller-skating rink.

Two others, including a police officer, suffered minor injuries.

More than 500 people were at the Skate Key in Mott Haven late Saturday night when a verbal disagreement erupted between two groups. It escalated into a physical fight, and then someone pulled out a knife, cops said.

One of the casualties, security guard Steven Feimster, 21, “was trying to break up the fight,” said a cousin who asked that her name not be printed. He was stabbed four times, she said.

Feimster and the other victims, whose names were withheld, were in stable condition, according to Lincoln Hospital.

Cops arrested four men on a variety of charges. Two of them – Keith Wells and Lerone Feimster – were charged with assaulting a police officer. It was unclear if Feimster and the security guard were related.

Leon Eloy, 19, who allegedly welded the knife, was charged with three counts of assault, and Sharmel Eloy, 18, was charged with robbery. It also was not clear if the Eloys were related.